<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>改变页面背景颜色</title>
</head>
<body>

<input type="button" value="红色" onclick="color('red')">
<input type="button" value="黄色" onclick="color('yellow')">
<input type="button" value="绿色" onclick="color('green')">


<script src="js/index.js"></script>
</body>
</html>